1. Technical Field
The present invention relates to an improvement of an electromagnetic induction connector which transmits electric power in a non-contact manner by the electromagnetic induction.
2. Related Art
Connectors etc. such as a socket plug, a such cable connector are used in a manner that they are connected so as to transmit electric power or electric signals when needed and disconnected when not needed. Almost of the such conventional connectors are arranged to transmit electric power by directly contacting electric conductive pieces. Thus, such a type of conventional connectors likely cause a trouble such as a contact failure, an electric shock, a leak etc. Further, such a type of conventional connectors etc. have a decisive drawback that these connectors can not be used in the water or a place such as a bath where the connectors may be watered due to the possibility of the occurrence of a leak.
The electromagnetic inductive coupling type connector arranged to obviate such a drawback is disclosed in Japanese Patent Publication Sho. 61-174607A, for example. FIG. 7 is a sectional view of the electromagnetic inductive coupling type connector disclosed in the publication. In the figure, a reference numeral 1 depicts U-shaped iron cores around which windings 3 are wound to constitute halves of a transformer, respectively. A reference numeral 5 depicts codes connected to the coils. A reference numeral 7 depicts casings made of material (for example, composite resin) which is electrically insulative and capable of transmitting magnetic force lines.
FIG. 7 is a diagram showing a state where connectors are separated. Upon use, a connector 9 and a connector 11 are coupled. In the combined state of the connectors, when AC voltage is applied from the code 5 of one of the connectors 9 and 11, the electric energy is transmitted to the other connector due to the magnetic induction. Since the transmission of the electric energy is performed by the magnetic induction, the electric energy can be transmitted without any trouble even if the casings 7 is made of electric insulator.
Thus, since the transmission of the electric energy is performed without directly contacting electric conductive pieces, a trouble such as a contact failure, an electric shock, a leak can be surely prevented.
However, the above electromagnetic induction connector is arranged in a manner as shown by a schematic diagram of FIG. 8 that the coils 3 are wound around the coupling portions 1a of the U-shaped iron cores 1, and upon coupling the connectors, the opposing end faces of two pairs of opposed leg portions 1b, 1b of the cores 1 are disposed so as to oppose to each other as shown in FIG. 9(A) thereby to form a path of the magnetic flux. Thus, there arises a problem that the transmission efficiency changes greatly depending on the abutment accuracy between the end faces of the two pairs of leg portions 1b, 1b. 
This is because when a deviation arises between the abutment portions of the opposed end surfaces of the two pairs of opposed leg portions 1b, 1b as shown in FIG. 9(B), magnetic fluxes B leak from the deviated portions A and hence the magnetic induction efficiency is degraded by the leaked magnetic fluxes. In contrast, in order to improve the abutment accuracy so as to reduce the abutment deviation, it is required to improve the manufacturing accuracy of the connectors, which results in the raising of the cost of the connectors.
The invention has been made in view of the above circumstances of the related art, and an object of the invention is to provide an electromagnetic induction connector which is cheap and can secure a high transmission efficiency regardless of the abutment accuracy of core portions.
In order to attain the above object, an electromagnetic induction connector includes:
a primary core including at least two first legs, each of the first legs defining a first tip end surface;
a secondary core including at lease two second legs, each of the second legs defining a second tip end surface opposed to said corresponding first tip end surface;
a primary coil wound around one of the first legs, extended from the first tip end surface of the one of the first legs and covering one of the second tip end surfaces; and
a secondary coil wound around the other second leg, extended from the second tip end surfaces of the other second legs and covering the other first tip end surface.
According to the electromagnetic induction connector thus arranged, since the coils wound around the leg portions of the cores are provided so as to explode from the tip end surfaces of the leg portions, when the primary and secondary cores are disposed so as to oppose to each other upon coupling the connectors, the partner-side leg portions are inserted within the coils thus extended. Thus, the tip end surfaces of the leg portions around which the coils are wound and the tip end surfaces of the partner-side leg portions disposed in opposite thereto (that is, gap portions forming a core discontinuous surface) are simultaneously surrounded by the coils. Accordingly, since the influence due to the leakage magnetic flux is reduced, the electromagnetic induction efficiency between the primary coil and the secondary coil can be improved. Further, since the influence due to the leakage magnetic flux is reduced without increasing the abutment accuracy, the manufacturing accuracy of the connectors may be low and so the manufacturing cost of the connector becomes low.
In the electromagnetic induction connector of the invention, the one of first legs is longer than the other first leg, the other second leg is longer than the one of second legs.
According to the electromagnetic induction connector thus arranged, such a configuration that the leg portions of the partner-side connectors are inserted within the coils can be attained easily by merely combining a pair of the connectors. In other words, if coils are provided around the leg portions with the long protruded lengths, the tip end surfaces of the leg portions around which the coils are wound are disposed so as to oppose to the tip end surfaces of the partner-side leg portions within the partner-side connectors at the time of combining the connectors. Thus, in this case, it is required to provide a mechanism capable of moving the coils to the position. Further, if the coils are provided so as to extend from the tip end surfaces of the leg portions with the long protruded lengths, it is meaningless since the lengths of the cores merely become longer. In contrast, according to the configuration of the invention, the pair of leg portions of each of the cores are formed to have different lengths, and the leg portions with the long protruded lengths are disposed so as to oppose to the leg portions with the short protruded lengths. Thus, it becomes possible easily to form such a configuration for inserting the leg portions within the coils, without providing a coil moving mechanism nor meaninglessly making the lengths of the leg portions of the cores long. The electromagnetic induction connector further includes:
a housing covering the primary core so that the first tip end surface of the longer first leg is accommodated in the housing; and
a housing covering the second core so that the second tip end surface of the longer second leg is accommodated in the housing.
According to the electromagnetic induction connector thus arranged, the tip end surfaces of the leg portions with the long protruded lengths are housed within the housings. of course, the tip end surfaces of the leg portions with the short protruded lengths are housed within the housings. That is, the cores do not protrude from the housings. Thus, since the cores thus protruded do not contact to other members, the cores can be prevented from being damaged and also other members can be prevented from being damaged.
An electromagnetic induction connector of the invention includes:
a primary core including at least two first legs, each of the first legs defining a first tip end surface;
a secondary core including at lease two second legs, each of the second legs defining a second tip end surface opposed to the corresponding first tip end surface;
a primary coil wound around and movable with respect to one of the first legs; and
a secondary coil wound around and movable with respect to one of the second legs,
wherein the primary coil covers the second tip end surface of the other second leg by moving the primary coil toward the other second leg, the secondary coil covers the first tip end surface of the other first leg by moving the secondary coil toward the other first leg.
According to the electromagnetic induction connector thus arranged, since the coils are provided so as to move freely with respect to the leg portions, after coupling the connectors, the coils are moved and protruded from the tip end surfaces to simultaneously cover the tip end surfaces of the partner-side leg portions. Thus, it is not necessary to form the leg portions of each core to have the difference lengths. As a result, since the leg portions of each core can be formed to have the same protruded length, the coupling end surfaces of the connectors to be coupled can be formed as flat surfaces.